The present invention relates to a data retrieving apparatus and method thereof and, more particularly, to a database system or an interface system between a database system and users, and method of retrieving data.
Associative retrieval is performed as primary basic operation of data retrieval in a database system. The associative retrieval performed in the general database system is pattern matching retrieval operation.
With respect to semantic relation between data, identity or difference of data has been determined on the basis of description written statically and explicitly with respect to the relation between data.
However, in the retrieving operation using pattern matching, a user is unable to retrieve data having the same meaning but represented by the different representation forms, or data having similar meanings. Moreover, the pattern matching cannot deal with polysemy of words.
Furthermore, in the determining operation of determining identity and difference of data on the basis of the statically-described relation, the determination is made with some ambiguousness. For instance, in a method of inquiring for synonyms utilizing a thesaurus, synonyms are statically decided at the time of designing the thesaurus, and the definition of synonymity is ambiguous.
However, it is considered that the semantic identity and difference between data dynamically changes depending on the context and condition. Therefore, in the above-described determination of determining identity and difference of data based on the statically-provided relations, ambiguousness cannot be excluded.